sign up for your fretrial today at constantcontact.com/try. >>> right now on "andrea mitchell reports" the candidates hold their last rehearsals before the showdown in denver. mitt romney picks up an endorsement from john elway. people want to know who's going to win and score the punches. it's not winning or losing or the people themselves, the president or myself, it's about something bigger than that, these debates are an opportunity for each of us to describe the pathway forward for america that we would choose. >> president obama rehearsing in suburban las vegas took a break to deliver pizzas to his local campaign workers. >> it's very nice, you know. we're -- you know, although basically they're keeping me indoors all the time, it's a drag. they're making me do my homework. >> and how much will the debate influence voters. we have our exclusive sneak peek at our new nbc news/"wall street journal" pol